Absolute frame in Kinetic Theory
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From: colp on 21 Jul 2010 19:08 On Jul 22, 10:12 am, PD <thedraperfam...(a)gmail.com> wrote: > On Jul 21, 4:45 pm, colp <c...(a)solder.ath.cx> wrote: > > What is your point? > > That there is nothing in kinetic theory that points to or relies on an > absolute frame. (reposting reply to similar assertion by Paul Stowe) Nope. For example, take two molecules, each with mass m, and separated by distance d. Give the molecules velocities such that they will approach each others center of mass and collide at time t. The calculated energy of the collision will depend on how you measure your velocities. For either molecule, the relative velocity of the other molecule will be d/t or -d/t. The calculated energy of collision is 1/2 mv^2 = 1/2 m.d^2/t^2, since one molecule is deemed to be stationary. If, instead, we say that each molecule is moving toward a stationary collision point, then v = d/2t or -d/2t The calculated energy of collision is now 2 * 1/2 mv^2 = m.d^2/4t^2 = 1/2 m.d^2/2t^2 The two calculations disagree by a factor of two.
From: Inertial on 21 Jul 2010 19:49 "colp" wrote in message news:4c7320f9-cb92-4e16-a4ec-55a618cb1d47(a)h40g2000pro.googlegroups.com... > >On Jul 22, 10:12 am, PD <thedraperfam...(a)gmail.com> wrote: >> On Jul 21, 4:45 pm, colp <c...(a)solder.ath.cx> wrote: > >> > What is your point? >> >> That there is nothing in kinetic theory that points to or relies on an >> absolute frame. > >(reposting reply to similar assertion by Paul Stowe) > >Nope. Wrong > For example, take two molecules, each with mass m, and separated >by distance d. Give the molecules velocities such that they will >approach each others center of mass and collide at time t. The >calculated energy of the collision will depend on how you measure your >velocities. Yes it will .. that simply means that the value for energy (like velocity etc) is frame dependent. That does NOT mean there is an absolute frame. Try again
From: eric gisse on 21 Jul 2010 12:39 colp wrote: > On Jul 22, 10:12 am, PD <thedraperfam...(a)gmail.com> wrote: >> On Jul 21, 4:45 pm, colp <c...(a)solder.ath.cx> wrote: > >> > What is your point? >> >> That there is nothing in kinetic theory that points to or relies on an >> absolute frame. > > (reposting reply to similar assertion by Paul Stowe) > > Nope. For example, take two molecules, each with mass m, and separated > by distance d. Give the molecules velocities such that they will > approach each others center of mass and collide at time t. The > calculated energy of the collision will depend on how you measure your > velocities. Duh. [snip rest of idiocy]
From: PD on 21 Jul 2010 23:52 On Jul 21, 6:08 pm, colp <c...(a)solder.ath.cx> wrote: > On Jul 22, 10:12 am, PD <thedraperfam...(a)gmail.com> wrote: > > > On Jul 21, 4:45 pm, colp <c...(a)solder.ath.cx> wrote: > > > What is your point? > > > That there is nothing in kinetic theory that points to or relies on an > > absolute frame. > > (reposting reply to similar assertion by Paul Stowe) > > Nope. For example, take two molecules, each with mass m, and separated > by distance d. Give the molecules velocities such that they will > approach each others center of mass and collide at time t. The > calculated energy of the collision will depend on how you measure your > velocities. > > For either molecule, the relative velocity of the other molecule will > be d/t or -d/t. > The calculated energy of collision is 1/2 mv^2 = 1/2 m.d^2/t^2, since > one molecule is deemed to be stationary. > > If, instead, we say that each molecule is moving toward a stationary > collision point, then v = d/2t or -d/2t > The calculated energy of collision is now 2 * 1/2 mv^2 = m.d^2/4t^2 = > 1/2 m.d^2/2t^2 > > The two calculations disagree by a factor of two. First of all, the principle of relativity does NOT mean that the VALUE of physical quantities are the same in all reference frames. Secondly, please consider what you mean by "energy of collision". The energy of collision is NOT the total kinetic energy available. I'll give you an example. Consider a completely inelastic collision where two equal masses collide and then stick together. This will involve a transformation of kinetic energy into energy of deformation (or reconformation), heat, sound, etc. The completely inelastic case is the case where the maximum amount of kinetic energy is so transformed. I'd like for you to calculate this energy transformed for this collision as viewed in two reference frames, just as you've done above: One where one of the masses is initially stationary and the other is moving at v; and one where both masses are approaching at v/ 2. Please remember that to find the final velocities in both cases you will need conservation of momentum. As you do this, please keep in mind that this is a FRESHMAN exercise.
From: mpc755 on 22 Jul 2010 04:40
On Jul 21, 11:52 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Jul 21, 6:08 pm, colp <c...(a)solder.ath.cx> wrote: > > > > > On Jul 22, 10:12 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Jul 21, 4:45 pm, colp <c...(a)solder.ath.cx> wrote: > > > > What is your point? > > > > That there is nothing in kinetic theory that points to or relies on an > > > absolute frame. > > > (reposting reply to similar assertion by Paul Stowe) > > > Nope. For example, take two molecules, each with mass m, and separated > > by distance d. Give the molecules velocities such that they will > > approach each others center of mass and collide at time t. The > > calculated energy of the collision will depend on how you measure your > > velocities. > > > For either molecule, the relative velocity of the other molecule will > > be d/t or -d/t. > > The calculated energy of collision is 1/2 mv^2 = 1/2 m.d^2/t^2, since > > one molecule is deemed to be stationary. > > > If, instead, we say that each molecule is moving toward a stationary > > collision point, then v = d/2t or -d/2t > > The calculated energy of collision is now 2 * 1/2 mv^2 = m.d^2/4t^2 = > > 1/2 m.d^2/2t^2 > > > The two calculations disagree by a factor of two. > > First of all, the principle of relativity does NOT mean that the VALUE > of physical quantities are the same in all reference frames. > > Secondly, please consider what you mean by "energy of collision". The > energy of collision is NOT the total kinetic energy available. > > I'll give you an example. Consider a completely inelastic collision > where two equal masses collide and then stick together. This will > involve a transformation of kinetic energy into energy of deformation > (or reconformation), heat, sound, etc. The completely inelastic case > is the case where the maximum amount of kinetic energy is so > transformed. > > I'd like for you to calculate this energy transformed for this > collision as viewed in two reference frames, just as you've done > above: One where one of the masses is initially stationary and the > other is moving at v; and one where both masses are approaching at v/ > 2. > > Please remember that to find the final velocities in both cases you > will need conservation of momentum. > Why are downgraded photon pairs not required to have opposite angular momentums in order to conserve the original photons momentum in order for there to be conservation of momentum in order for there to be instantaneous action at a distance? You still have not answered the questions. Explain what occurs physically in nature to cause spacetime to curve but not move. Explain what occurs physically in nature which allows a C-60 molecule to enter, travel through, and exit multiple slits simultaneously without losing momentum. Explain what occurs physically in nature when mass converts to energy. Explain what occurs physically in nature which allows the future to determine the past. Explain what occurs physically in nature to cause gravity. Dark Matter Displacement explains what occurs physically in nature in all of the above. Dark matter is displaced by matter. Dark matter is not at rest when displaced. Displaced dark matter exerts pressure towards the matter. A moving particle has an associated dark matter displacement wave. Physical effects caused by matter converting to dark matter is energy. Mass is conserved. The future does not determine the past in the physics of nature. Pressure exerted by displaced dark matter towards matter is gravity. |